Exhaust manifold



June 5, 1945. P. E. MERCIER 2,377,708

EXHAUST MANIFOLD Filed Jan. 15, 1941 '3 Sheets-Sheet l fnl/enfor p/f/Q/Qf fRA/fJTMfPC/fR MRQW June 5, 1945. P. E. MERCIER 2,377,708

EXHAUST MANIFOLD Filed Jan. 15, 1941 3 Sheets-Sheet 2 [12 yen for P/f/PAf L E/v5.37 MERC/f/P June 5, 1945. P. E. MERCIER EXHAUST MANIFOLD Filed Jan. 15, 1941 5 Sheet s-Sheet s Patented June5, 1945 EXHAUST MANIFOLD Pierre Ernest Mercier, New York, N. Y., assignor, by mesne assignments, to Helfeda, S. A., Geneva, Switzerland, a corporation of Switzerland ' Applicatlonlanuary 15, 1941, Serial No. 374,425

In France February 7, 1940 3 Claims.

The invention relates to exhaust manifolds for multicylindered airplane engines.

The main object of the invention is to group the exhausts of the engine cylinders in twos by providing an exhaust manifold common to each pair of cylinders.

Another object of the invention consists in providing a special form of such manifold combined with an exhaust pipe.

Still another object of the invention is to have forms of said manifold particularly adapted for use with a double-row radial engine.

The invention will be better understood by means of the attached drawings, in which:

Fig. 1 represents a half-view, taken along line l-I of Fig. 2 and looking in the direction of the arrows, of a double-row radial engine cowling without valve, by way of example, having exhaust members according to the invention.

Fig. 2 shows a bottom view of the same cowling.

Fig. 3 is a sectional view taken along line 33 of Fig. 1 and looking in the direction of the arrows.

Fig. 4 shows in perspective a manifold in accordance with the invention adapted to the front cylinders of a double-row radial engine.

Fig. 5 shows in perspective a manifold according to the invention adapted to the rear cylinders of a double-row radial engine.

Figs. 6 and '7 show respectively in lateral view and in perspective a variation of the manifold with a bulbous body form as connected to one of the cylinder pipes.

Figs. 8 and 9 in similar fashion show respectively, in a lateral view and in perspective, another variation in which the two cylinder pipes are connected to the side of the bulb-shaped portion of the manifold.

Assuming that the duration of the time of exhaust in an engine extends over more than 250 of the revolution of the crankshaft, it will be seen that without causing the end of an exhaust to coincide with the beginning of another, it is possible to have two cylinders exhaust into the same member if their exhaust times are separated approximately by one revolution of the crankshaft.

In multiple-row radial engines this is in general the case with two adjacent cylinders of the same radial row at nearly 1/11. turn, nbeing the number of cylinders in a radial row. i

In its most general aspect, the invention consiststhereforein grouping the exhausts of such cylinders in twos.

In the particular case of double-row radial engines such a grouping would give rise to overlapping of exhaust members of both radial rows (on account of the overlapping arrangement of the cylinders of the two radial rows). The invention therefore provides for this case in having the exhausts of the front radial rows end in members common to each pair of adjacent cylinders in the form of a curved nozzle, the discharge slot of which is directed to the rear and permits a flow of insulating air between the ases and the cowling,

while the exhausts of the cylinders of the rear radial row are arranged between the cylinders in common to each pair of said cylinders and by utilizing the flattening combined with the curvature and sheet of insulating air between the pipe and the motor cowling.

The preceding combination offers a great many advantages beside the increase of propulsive effect, on account of the fact that the exhaust manifolds are reduced as well as the exhaust members themselves, and lend themselves particularly well to the construction of a motor cowling with an efficient air circulation, provided with means for the removal of air arranged under the different gas exhaust evacuation slots.

Moreover, the exhaust members of the front radial row of cylinders, though being provided with discharge openings allotted to each pair of adjacent cylinders, may be assembled on a single crown forming the front tip of the cowling and permitting a device for the production of hot air to be readily established.

According to a variation applicable either to a double-row radial engine or to any multicylindered engine, the exhaust members common to two cylinders are characterized by a cavity of bulbous form, into which one or the two exhaust pipes enter tangentially, the discharge of the gases being assured along a gaseous sheet detaching itself tangentially from the bulb-shaped body and passing out to the rear of the surface of the motor fairing.

Among other things this arrangement offers the advantage of reduced space and allows of combining the exhausts of two adjacent cylinders, insuring at the level of the exhaust slot a more regular rate of flow of gas than in the case of individual pipes.

This more regular rate of flow promotes both the propulsive effect of the exhaust and the drive of the cooling air which is admitted under the evacuation rim of, the gases'rlaving the device.

Of course, the invention lends'itself to all sorts of variations of embodiment, andjspecia lly allows of the production of hot'air (necessary, for example, for heating the carburetors), by means plane. 4

of an inner tube, concentric with the bulb-shaped body, and provided with a simple or return circulation.

Now, with reference to Figs. 1, 2 and 3, a pro-' 3, while the corresponding flange l2 serves to secure the exhaust pipe to cylinder 8.

The exhaust pipe common to each pair of rear cylinders is shown at 6 in Fig. 3; it'is provided with a discharge slot H. The pipe common to provided with a discharge slot It. The sheets of I each pair of front cylinders is seen at 5 and is air caused by the cooling of the motor and insulating the cowling from the exhaust gases pass through the outlets seen at 3| and 32, which can be adjusted by moving the fairing 33, controlled by articulated rods indicated diagrammatically at 1. To this end the fairing 33 is made movable relatively to the cowling and is secured to a plurality of links 40, one of which is shown in Fig. 3. Each link 49 is pivotally secured to a second link 4| mounted intermediate its ends on a pivot 42 supported on a. bracket 43 fastened to the engine. Secured to the free end of each link 4| is an actuator rod 44. By moving the rods 44 forwardly or rearwardly, the fairing 33 may be moved rearwardly or forwardly with respect to the cowling, thus enabling the size of the openings 3| and 32 to be adjusted as desired. In Figure 3 of the drawings it is seen that one of the terminal ends of the fairing 33 lies adjacent the exhaust end of the pipe 6 (reference being made at this point to the upper half of Figure 3) while (reference being made to the lower half of the same figure) the fairing extends over the forward end portion of the cowling of the The members 5 are carried and Joined together by means of the crown 1, which serves as a heating surface for the production of hot air admitted at the front nose 45 of the cowling through the slot 3. For this purpose, the nose 45 of the cowling and the crown form an annular chamber 30 within which is disposed a laterally extending bafiie 46 secured to the bell-shaped fairing It. Cool air is admitted through the annular slot 3 and over the baille 46 into contact with the crown I where it is heated by heat from the exhaust gases in the exhaust pipes 5. The heated air is conducted from the chamber 3|) formed by the nose 45 and the crown I] through a pipe to the various points on the airplane where it may be needed. r

A fairing l0, which is partly fixed and partly movable with the airplane propeller, cooperates {with a rearwardly extending bell-shaped fairing It to form an air inlet l6 for supplying cooling air for the engine cylinders. To this end, the fairing I6 is provided with a plurality of rearwardly extending scoop-like members |6"a and |6b which direct air from the inlet IE to the tops of each of the cylinders in the two rows.

In operation, the rotating propeller (not shown) supplies cooling air through the inlet l6. Part of the air admitted through the cool-- ing inlet l6 passes over the cooling fins on the cylinders in both rows (Fig. 3) and is discharged through the discharge outlets 3|, 32. Another part of the cooling air admitted through the inlet 2,877,708 7 I I3 is directed by the scoop like members Ila and Meanwhile, the exhaust gases from adjacent pairs of cylinders in the forward row are exhausted from exhaust pipes like the pipe 6 in Fig. 3, through the slot IS, the cooling air being discharged through the slots 3| between the exhaust gases and the cowling. In similar fashion, the exhaust gases from adjacent pairs of cylinders in the rear row are exhausted from exhaust pipes like the pipe 3 in Fig. 3, through the slot M, the cooling air being discharged through the slots 32 between the exhaust gases and the cowling.

As indicated above, by employing a common exhaust manifold for each pair of adjacent cylinders, the number of exhaust manifolds and exhaust pipes is cut in half, while a more regular rate of flow of exhaust gases is obtained in the discharge slots than is possible in the case where an individual exhaust manifold is used for each cylinder. This more regular rate-of flow of exhaust gases promotes both the propulsive effect of the exhaust and the drive of the cooling air which is discharged between the engine cowling and the exhaust gases.

In Figs. 4 and 5 we 'see, on a larger scale, the form of the double pipes in communication with each opposite cylinder exhaust flange of the same radial row. Fig. 4 refers to the front row, and Fig. 5 to the rear row of radial cylinders. The reference numbers 5, l5 l1, l3, l9 and 6, |2, |3 designate the same elements as in Figs. 1 to 3.

In Figs. 6 and 7, 2| and 22 designate two exhaust pipes fitted in any convenient manner with attaching flanges notshown, but similar to those shown at l8 and I9 or at l2 and I3 in Figs. 1 to 5, and which in the variation shown may evacuate the gases of any two cylinders of any engine. One of the exhaust pipes 2| enters a hollow bulbshaped body 23 tangentially through one of the ends of the latter, while the the other, 22, has a pipe doubly bent with a surface common with the side of the bulb-shaped body, one wall of which is eliminated as well as that of the pipe in the portion of the surface in question.

The end 24 of the exhaust pipe enlarges fanlike at 26 as it becomes thinner, in order to terminate at its widest part along the discharge slot at the outside, while assuming the shape and the contour of the engine cowling 25. The bulging or bulb-shaped body is truncated at its end opposite the first exhaust pipe 2| (at 21), and an air heating device with baflles (28) is introduced into the interior of the bulb-shaped'body at the level of said truncation. This device has two pipes, an interior open end pipe 36, and a concentric exterior one 31, respectively communicating with the pipe openings 38 and 39, allowing air to be heated to be drawn in from one pipe and fed to theengine from the other.

The outside cooling air flowing along the exterior surface of the exhaust member during the flight of the aircraft carrying the device flows around a deflector 23 and leaves at 30 under the lip of the pipe 24.

According to Figs. 8 and 9, the two exhaust pipes 34 and 35, similar to the pipes 2| and 22,

enter tangentially and symmetrically of the hol-- between the two exhaust gas admission pipes. This pipe expands and becomes thinner, as indicated in the preceding variation. The cooling system at the end of the pipe is similar to that shown in Fig. 6.

The heating circuit may in this case be provided with the pipe 40 passing from one end to the other through the gland and arranged along its axis.

I claim:

1. In an airplane engine with several cylinders arranged radially in a double-row, common manifolds intoeach of which the exhaust pipes of the gases of two adjacent cylinders of the front row discharge, each manifold being associated with one pair of cylinders only and evacuating the gases in an exhaust pipe individual for said manifold, said pipe having a progressively fiattened profile, so as to terminate in an elongated slot, and presenting a double curvature in the general direction of the evacuation of the gases with one portion curved substantially perpendicularly to the curvature of the other, and the arrangement being such that the gases are evacuated first toward the front of the engine and then guided to the discharge slot toward the rear, and a single crown on which are assembled all the exhaust members of the front radial row of cylinders.

2. In an airplane engine with several cylinders arranged radially in a double row, common manifolds into each of which discharge the exhaust passages of the gases of two adjacent cylinders oi the front radial row, each manifold being associated with one pair cylinders only and evacuating the gases in an exhaust pipe individual for said manifold, said pipe having a progressively flattened profile, so as to terminate in an elongated slot, and presenting a double curvature in the direction of the evacuation of the gases with one portion curved substantially perpendicularly to the curvature of the other, and, the arrangement being such that the gases are evacuated first toward the front of the motor and then guided toward the discharge slot to the rear, and a single crown on which are assembled all the exhaust members of the front radial row, the interior of said crown forming a part of a circuit for air heated by contact with said members.

3. In an airplane, in combination with a double row, radial engine having a plurality of cylinders, a cowling for the engine, means forming in the front of said cowling an inlet for cooling air, means for directing air from said inlet to said engine cylinders, means forming in the cowling in front of said cylinders a first discharge outlet for cooling air, means forming in the cowling behind said first discharge outlet a second discharge outlet for cooling air, a first group of common exhaust manifolds for adjacent pairs of engine cylinders in the forward row, conduits for directing exhaust gases from each pair of cylinders to the manifold corresponding thereto, an exhaust conduit for each manifold, each of said exhaust conduits having a progressively flattened profile terminating in an exhaust outlet adjacent said first cooling air discharge outlet, and having curved portions for directing the exhaust gases in a forwardly direction and then in a rearwardly direction to said exhaust outlet, means including portions of said exhaust conduits for directing part of the heatedv cooling air to said discharge outlet such that it is discharged between the exhaust gases from said exhaust outlets and the engine cowling, common exhaust manifolds for adjacent pairs of engine cylinders in the rear row, conduits for directing exhaust gases from each pair of cylinders to the manifold corresponding thereto, an exhaust conduit for each manifold, each of said exhaust conduits having a progressively flattened profile terminating in an exhaust outlet disposed adjacent said second cooling air discharge outlet, and having a curved portion for directing the exhaust gases to said exhaust outlet, and means including portions of said last named exhaust conduits for directing another part of the cooling air to said second discharge outlet such that it is discharged between the exhaust gases from said last named exhaust outlets and the engine cowling.

PIERRE ERNEST MERGIER. 

